SCSSR2_RDF
~(SCSSR2_ER | SCSSR2_BRK | SCSSR2_RDF | SCSSR2_DR));
& ~(SCSSR2_ER | SCSSR2_RDF | SCSSR2_DR));
if (scif_ssr_read() & (SCSSR2_RDF | SCSSR2_DR)) {
} while (scif_ssr_read() & (SCSSR2_RDF | SCSSR2_DR));
& ~(SCSSR2_ER | SCSSR2_BRK | SCSSR2_RDF | SCSSR2_DR));
scif_ssr_write(scif_ssr_read() & ~(SCSSR2_RDF | SCSSR2_DR));